* lib/adlint/exam/c_builtin/cc1_check.rb : Fix bad W0570 code check
  degraded during supporting context-tracing.

* features/code_check/W0570.feature : Add scenario to reproduce a known
  bug.
* lib/adlint/cc1/interp.rb : Fix bad context-tracing during or after
  evaluation of an iteration statement.
* lib/adlint/cc1/object.rb : Ditto.
* lib/adlint/cc1/value.rb : Ditto.

* lib/adlint/cc1/trace.rb : Revise context-tracing interface in order
  not to output context messages about futural controlling-expressions.
* lib/adlint/exam/c_builtin/cc1_check.rb : Ditto.